Talking to the employees of the company you are visiting is very different than talking to employees. Basically, you have to be polite and formal when dealing with them.

"Hi Mark, I'm Alex from ABC Consulting. It's nice to meet you."

During this stage, you might be engaged in small talk such as how your flight was or how the weather is over in your city, but if not, then you can get straight to work. You might need to know where you will be working. Only ask this if they never tell you. But chances are, they will let you know before you ask.

"Where will I be working this week?"
"Where is your office located?"
"Is your office relatively close to where I will be working?"

You might need to ask who you will be working with. But again, don't ask this too early, you should give them a chance to answer.

"Who will I be working with this week?"

These previous questions should only be used in rare cases the other person doesn't tell you. The next couple of sentences are more likely.

"Who should I contact if I have a question regarding inaccurate data?"
"Who should I contact if I have a question with this type of problem?"

"I am going to be calling my manager frequently with critical updates. What phone should I use?"

"How long does it take to get to the airport from here?"
"How bad is the traffic around this time to the airport?"

"Where is the closest place to eat around here?"
"Is there a fast food restaurant near by?"

"Does this building have a cafeteria?"
"Do you have a cafeteria close by?"